CONTINUOUSLY OPERATED PURIFICATION BY DISTILLATION OF THE 1,2-PROPYLENE GLYCOL FORMED IN THE COPRODUCT-FREE SYNTHESIS OF PROPYLENE OXIDE

摘要

The invention relates to a continuous method of purification by distillationof 1,2-propylene glycol that accumulates as a by-product during the synthesisof propylene oxide. Said method is characterised in that the mixture that isproduced during said synthesis, which contains the 1,2-propylene glycol, isseparated in a dividing wall column into a low-boiler, medium-boiler and high-boiler fraction and that 1,2-propylene glycol is drawn off laterally from thecolumn as a medium boiler.